Rotary piston internal-combustion engine



P 8, 1953 J. E. PRlD HAM 2,651,177

ROTARY PISTON INTERNAL-COMBUSTION ENGINE Filed Nov. 8, 1949 5Sheets-Sheet 1 gal Iv vf/vnm Z1155 [ye/em 7%06 4;

Sept. 8, 1953 J. E. PRIDHAM ROTARY PISTON INTERNAL-COMBUSTION ENGINE 3Sheets-Sheet 2 Filed Nov. 8, 1949 13y VE/VfdK Sept. 8, 1953 J. E.PRIDHAM 2,651,177

v RC TRY PISTON ZNTEFNAL-COMBUSTION ENGINE Filed Nov. 8, 1949 aSheets-Sheet s Eff frat Jams [nae/2K baby/9%;

Patented Sept. 8, 1953 ROTARY PISTON INTERNAL-COMBUSTION ENGINE JamesEverard Pridham, Parkstone, England Application November 8, 1949, SerialNo. 126,151 In Great Britain November 2, 1948 4 Claims. (01. (ill-39.61)

This invention relates to rotary piston internal combustion engines andis concerned with the provision of a generally improved engine of thistype having a high mechanical efficiency and which is generallyeconomical in operation.

According to the present invention, a rotary piston internal combustionengine comprises a stator having an annular channel opening into oneface thereof and a rotatable wheel or disc secured on a driving shaftand arranged, in conjunction with said channel, to provide an annularcylinder having at least one fuel inlet and at least one exhaust outlet,and further comprises at least two pistons or vanes mounted on the saidwheel or disc and arranged to work in the said cylinder, and at leasttwo rotary abutments, one of which is shaped to provide at least onecombustion recess in its outer wall surface, the abutments being indriven connection with the said shaft and arranged to work in abutmentcylinders which overlap the annular cylinder so that the abutmentstraverse the said annular cylinder during their rotation and divide itintermittently into a number of compartments, the arrangement being suchthat fuel can be drawn into the cylinder by one piston, compressed intoa combustion recess by a following piston, fired in said combustionrecess and then released behind said following piston to drive thepiston around the said cylinder.

In order that the invention may be clearly understood and readilycarried into effect one embodiment thereof will now be described indetail with reference to the accompanying drawings, wherein:

Figure 1 is a cross-sectional elevation of the engine, the main shaftbeing partially broken away,

Figure 2 is a section on the line II--II of Figure 1, the rotor havingbeen moved through 120 in a clock-wise direction for purposes ofillustration, and

Figure 3 is a part sectional elevation on the line IIIIII of Figure 2.

Referring now to the drawings, the stator is in the form of asubstantially circular plate I having a concentric annulus I a.extending around the marginal edge of the rear face, a channel 2 beingformed in said annulus, said channel opening into the opposite or frontface of the plate. A web portion 3 extending diametrically across theannulus is formed on the rear face of the.

plate I and a central concentric aperture is formed through the plateand web portion, the latter being provided with a boss 3a as shown inFigure 1. A rotatable disc or wheel 4, having a raised annular rim 4aaround the outer margin of one face, and secured on the main shaft 5which passes freely through the aperture in the plate and web with theinter-position of a. bearing bushing I3, is arranged to co-operate withthe channelled front face of the plate I so that the rim 4a, enters thechannel 2 to form an enclosed working space or cylinder. Secured atdiametrically opposed points on the rim 4a of the wheel 4, and extendingsubstantially perpendicularly from the rim surface, are two vanes orpistons I which are arranged to work in the enclosed annular workingspace or cylinder 2.

The plate I is formed with crescent-shaped extensions Ib opposite theends of the web 3 and the outer wall of the annulus la is formed withcorresponding extensions I c which, together with the adjacent end facesof the web 3 form the walls of abutment cylinders 20. which overlap themain cylinder 2. Conical projections Id are formed on the rear face ofthe plate I concentrically within the abutment cylinder 20 the reducedends of these projections terminating in fixed spindles 8. The abutmentcylinder walls are suitably interrupted and the projections Id aresuitably channelled so that the cylinder 2 is continued therethroughwithout interruption. Hollow rotary abutments 9 having cylindrical outersurfaces and conical inner surfaces are mounted for rotation within theabutment cylinders 2a about the projections Id, the abutments beingprovided with concentric sleeve-like extensions I0 which engage aroundthe spindles 8. Bearing bushes II are interposed between the extensionsI0 and spindles 8 and the abutments are held against longitudinaldisplacement relatively to the spindles by means of nuts I2 which latterare screwed onto the outer ends of the spindles. The abutments 9, duringtheir rotation, traverse the cylinder 2 and diametrically opposed slots9a are formed in the walls of the abutments 9, to permit the passage ofthe pistons I therethrough when the position of the abutments is suchthat the slots 9d are in the path of the pistons.

The abutments 9 are rotated about the spindles 8 in timed relationshipwith the pistons 'I by means of pinions I3 keyed on the sleeve-likeextensions Ill and driven by a pinion I4 keyed on the main shaft 5,through intermediate idler pinions I5. The pinions I5 are rotatablymounted on stub shafts I6 carried by cover plates I! which are fittedover the open ends of the abutment cylinders and bolted to flanges I-earound the outer edges of the cylinders. The pinions i5 are retained onthe shafts 16 by nuts Ilia. The plates H are each provided with acentral apertured boss l8 which is shaped to fit over and provide abearing for the adjacent sleeve-like extension it with theinter-position of a bearing bush l8a.

Diametrically opposed recesses 9b are formed in the outer wall of one ofthe abutments 9, these recesses being arranged, when opposite the portion ic of the wall of the abutment cylinder, to form closed combustionchambers in conjunction with the said wall portion. (See Figure 2.) Aspark plug I9 is mounted in this wall portion of the abutment cylinderla in the path of the recesses 9b. W

The wheel or disc 4 is covered by means of a cover plate 20 which isbolted to the front face of the plate I and formed with a centralaperture surrounded by an upstanding bushed boss 20a through which theshaft 5 extends and for which it provides a bearing, A fuel inlet 21 isformed in the wall of the cylinder 2 on one side of, and adjacent, theplain abutment 9, i. e. that which is not provided with the combustionrecesses 9b, and an exhaust outlet 22 is provided in the wall of thecylinder on the other side of and adjacent the same abutment. The casingl is provided with a water jacket 23 which, in this embodiment, extendsaround that part of the cylinder wall in which the working strokeoccurs.

The abutments 9 are rotated in timed relationship with the wheel 4 sothat when a piston 1 reaches an abutment 9 during rotation of the wheel4, the abutment is in a position in which the piston can pass throughthe slots 90. therein without interruption.

In operation, a piston 1 retreating from the fuel inlet port 2 l asshown in Figure 2, induces or draws a charge into the cylinder 2 behindthe piston and passes through the abutment. This charge is compressed bythe following piston into a combustion recess 9b in the rotatingabutment 9 which the said following or compressing piston isapproaching. As the compressing piston gets close to this abutment, theabutment moves into a position in which the piston can pass therethroughand substantially at the same time the combustion recess containing thecharge is moved opposite the wall portion [c of the abutment cylinderwhich effectively closes the combustion recess 9b as aforesaid to form aclosed combustion chamber. (A combustion chamber in the closed positionis illustrated in Figure 2.) The continued rotation of the abutmentcarries the charge past the sparking plug l! at the same time as thepiston is passing through the abutment and the timing is such that therelease of the fired charge into the expansion section of the cylindertakes place in rear of the piston just after the piston has passedthrough the abutment so that the piston is driven round within thecylinder. Whilst being thus driven the leading surface of the pistonserves to scavenge the cylinder and eject the exhaust gases of theprevious explosion through the exhaust outlet 22, the plain abutmentbeing then in the position in which it blocks the cylinder asillustrated. The plain abutment moves into a position in which the slots9a are aligned with the cylinder as the piston approaches and the pistonpasses therethrough and draws in behind it a fresh charge at the sametime compressing the charge which has previously been drawn in by theother piston, the cycle then continuing as previously.

As will be understood, the timing is so arranged that a piston advancingtowards an abutment is either compressing a charge into a compressionrecess or alternatively sweeping exhaust gases through the exhaustoutlet, and a piston retreating from an abutment is either performingthe working stroke or the induction stroke. There are thus two firingstrokes per revolution of the rotor.

Owing to the constant high speed of the surfaces of the working parts inthe engine above described, gas-sealing devices as embodied in thepresent day reciprocating piston engine, in which the piston speed iscomparatively low at the time of maximum pressure, will not benecessary. If

. the co-operating surfaces of the rotating and stationary working partsare left unpolished, unmachined or even suitably grooved, gas eddieswill prove sufiicient to restrict gas leakage to a reasonable minimum.Moreover it is probable that such carbonisation as is permitted by therelative movements of the parts will improve performance.

The engine as described may be constructed in duplicate form withpistons working in annular cylinders on both sides of the wheel or rotorplate, and with abutments arranged face to face as desired, the centralrotor revolving between them. Also any number of these engines may bearranged to work on a common shaft in order to form a complete powerunit.

The uses of this engine cover all cases where rotary power is requiredand owing to its shape and possible multiplication on one shaft it iseminently suitable for propeller-driven aircraft or for embodimentwithin a composite propeller and jet unit. A variation of thecompression and expansion ratio may be made if desired by a modifiedpositioning of the abutments.

At the end of a compression stroke, there will remain a portion ofcompressed air or vapour which is not admitted to the combustionchamber, and a part of this cool air or vapour will be carried throughthe abutment by the piston and will be used to cool those parts of theengine most exposed to high temperatures. The remaining part may bereleased to the rear of the piston in question by means of anenlargement of the annular cylinder at the appropriate point, thisreleased air or vapour being compressed once more by the followingpiston so that an increasing compression pressure is built up.

Such auxiliary requirements as carburation, fuel injection, lubrication,ignition and cooling can be effected by any of the well known methods.

I claim:

1. A rotary internal combustion engine comprising a driving shaft, aco-operating circularly grooved stator and rotor mounted on said shaftand arranged to provide an annular cylinder therebetween which isconcentric with the shaft, at least two pistons mounted on said rotor towork in said cylinder, at least two abutment cylinders which overlapsaid annular cylinder, at least two slotted abutments mounted forrotation one in each said abutment cylinder so as to be capable oftraversing said annular cylinder to divide it intermittently into anumber of compartments, the slot in each said abutment being arranged topermit the passage of a piston there- .through when said slot iscoincident with the cylinder, and at least one of said abutments beingexternally recessed to provide, in conjunction with the associatedabutment cylinder wall. two diametrically opposed combustion chambers, agas inlet and an exhaust outlet in said annular cylinder one on eachside of an abutment, means for igniting fuel mixture in said combustionchambers and means for driving said abutments in timed relationship withsaid pistons whereby gas can be drawn into the annular cylinder by onepiston, compressed into a combustion chamber by a following piston,fired, released behind said following piston to drive it around thecylinder and finally exhausted by the next following piston.

2. A rotary internal combustion engine comprising a stator, a rotorco-operating with said stator to provide an annular working cylinder,shaft means on which said rotor is concentrically carried, two pistonsmounted at diametrically opposed points on said rotor and arranged towork in said cylinder, two diametrically opposed abutment cylinderswhich overlap said annular cylinder, two symmetrical abutments mountedfor rotation one in each said abutment cylinder so as to be capable oftraversing said annular cylinder and dividing it intermittently into anumber of compartments, each said abutment being hollow and having itswalls formed with diametrically opposed slots to permit the passage of apiston therethrough, and one of said abutments having two diametricallyopposed external recesses to provide, in conjunction with the associatedabutment cylinder wall, two opposed combustion chambers, a gas inlet andan exhaust outlet in said annular cylinder positioned adjacent to andone on each side of the non-recessed abutment, means for igniting fuelmixture in said combustion chambers in turn and means for driving saidabutments in timed relationship with said shaft means whereby gas can bedrawn into the annular cylinder by one piston, compressed into acombustion chamber by a following piston, fired, released behind saidfollowing piston to drive it around the cylinder and finally exhaustedby the next following piston.

3. A rotary internal combustion engine as claimed in claim 2 in whichsaid symmetrical rotary abutments are of hollow form having asubstantially cylindrical outer surface and a substantially conicalinner surface and each said abutment is mounted to revolve about aspindle which is also slotted for the passage of the pistonstherethrough and which is secured on the stator.

4. A rotary internal combustion engine comprising a co-operatingcircularly grooved stator and a rotor forming an annular cylindertherebetween, pistons mounted on said rotor to work in said cylinder, anumber of circular section hollow symmetrical rotary abutments arranged,on rotation, to divide said cylinder intermittently into a number ofcompartments, the walls of each said abutment being provided withdiametrically opposed slots to permit the passage of said pistonstherethrough when said slots are in alignment with the annular cylinder,two diametrically opposed combustion recesses provided in the outersurface of at least one said abutment, means for driving said abutmentsin timed relationship with said rotor, said piston functioning to supplyfuel under pressure to said combustion recesses in turn, means forigniting fuel in a combustion recess and subsequently releasing it todrive a piston around the annular cylinder, and means for exhaustingburnt fuel from said cylinder.

JAMES EVERARD PRIDHAM.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 1,069,742 Tygard Aug. 12, 1913 1,455,324 Cushman May 15, 19232,110,524 Hodges Mar. 8, 1938 2,418,793 Selden Apr. 8, 1947 2,466,759Baylin Apr. 12, 1949 FOREIGN PATENTS Number Country Date 812,870 FranceFeb. 15, 1937 381,625 Italy July 15, 1940

